Rapidly expanding usage of electronic microcircuits has resulted in a rapid advance in the art of producing articles in the nature of a micropattern of a functional material supported on or in a substrate base of a dissimilar material. Recently developed procedures employ, e.g., as a substrate for the microdevice, a base of silicon covered by silicon dioxide, and an electron resist covering the silicon dioxide, the resist being selectively irradiated by an electron beam in accordance with the micropatterning step to be performed, the irradiated resist then being removed to expose selected areas of the silicon dioxide, the exposed areas then being treated, as by etching, if necessary, the functional material then being applied, and the resist then being removed in the area which has not been irradiated, bringing the substrate to a condition suitable for the next micropatterning step. Typical requirements include diffusion of dopants into the silicon base in one or more selected areas, and provision of a conductive metal on defined areas of the silicon dioxide, and such requirements are met by different procedures each requiring use of an electron resist on which a portion of the micropattern is written by electron beam irradiation. It is common to use as the electron resist a synthetic polymer which is partially depolymerized by electron beam irradiation, the partially depolymerized material being removable by dissolution in, e.g., the corresponding monomer.
Though such prior-art procedures have achieved marked success, they are limited to those objectives which can be accomplished by treatments controlled by the presence or absence of the resist on the base. Further, such procedures require relatively extensive electron beam irradiation to "write" the pattern desired, and writing time has become recognized as a primary limiting factor. Finally, while such methods are now commonly used to produce micropatterns of very small size, with, e.g., conductive path widths as small as 1000 A, further reduction in the dimensions of the micropattern is highly desirable.